The physiology of circulation during swimming activity in rainbow trout

Abstract

From Introduction: Rainbow trout (Salmo gairdneri) were introduced into Europe from North America in the latter half of the last century. They can tolerate higher water temperatures and lower oxygen concentrations than the native brown trout (Salmo trutta). Rainbows grow faster than brown trout under similar conditions and are thus particularly attractive for artificial rearing methods. In Denmark there is a thriving rainbow trout farming industry producing about 9,000 metric tons annually which is largely exported for table use (Mills 1971).

In Britain production of rainbow trout for food is not on such a large scale but they form the basis of a considerable sport fishery. In Scotland and Northern England although rainbow trout reach sexual maturity they do not generally breed so the population is entirely dependent on restocking with hatchery reared fish, thus although living more or less wild in many British waters , this species is essentially an artificially managed resource upon which man can impose genetic selection (Donaldson and Olson 1957) as well as normal fishery controls. A detailed understanding of the biology and physiology of this species is hence of particular importance.